1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2006-2015, University of Amsterdam 7 VU University Amsterdam 8 All rights reserved. 9 10 Redistribution and use in source and binary forms, with or without 11 modification, are permitted provided that the following conditions 12 are met: 13 14 1. Redistributions of source code must retain the above copyright 15 notice, this list of conditions and the following disclaimer. 16 17 2. Redistributions in binary form must reproduce the above copyright 18 notice, this list of conditions and the following disclaimer in 19 the documentation and/or other materials provided with the 20 distribution. 21 22 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 30 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 32 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 POSSIBILITY OF SUCH DAMAGE. 34*/ 35 36:- module(www_browser, 37 [ www_open_url/1, % +UrlOrSpec 38 expand_url_path/2 % +Spec, -URL 39 ]). 40:- autoload(library(lists),[member/2]). 41 42:- if(exists_source(library(process))). 43:- autoload(library(process), [process_create/3]). 44:- endif. 45 46:- multifile 47 known_browser/2. 48 49/** <module> Open a URL in the users browser 50 51This library deals with the highly platform specific task of opening a 52web page. In addition, is provides a mechanism similar to 53absolute_file_name/3 that expands compound terms to concrete URLs. For 54example, the SWI-Prolog home page can be opened using: 55 56 == 57 ?- www_open_url(swipl(.)). 58 == 59*/ 60 61%! www_open_url(+Url) 62% 63% Open URL in running version of the users' browser or start a new 64% browser. This predicate tries the following steps: 65% 66% 1. If a prolog flag (see set_prolog_flag/2) =browser= is set 67% and this is the name of a known executable, use this. The 68% flag may be set to `Command-Mode`, where mode is one of `fg` 69% or `bg`, requesting Command to run in foreground or background 70% mode. Default is `bg`. 71% 72% 2. On Windows, use win_shell(open, URL) 73% 74% 3. Find a generic `open' comment. Candidates are =xdg-open=, 75% =open= or =|gnome-open|=. 76% 77% 4. If a environment variable =BROWSER= is set 78% and this is the name of a known executable, use this. 79% 80% 5. Try to find a known browser. 81% 82% @tbd Figure out the right tool in step 3 as it is not 83% uncommon that multiple are installed. 84 85www_open_url(Spec) :- % user configured 86 expand_url_path(Spec, URL), 87 open_url(URL). 88 89open_url(URL) :- 90 current_prolog_flag(browser, Browser), 91 expand_browser_flag(Browser, Command, Mode), 92 has_command(Command), 93 !, 94 run_command(Command, [URL], Mode). 95:- if(current_predicate(win_shell/2)). 96open_url(URL) :- % Windows shell 97 win_shell(open, URL). 98:- endif. 99open_url(URL) :- % Unix `open document' 100 open_command(Open), 101 has_command(Open), 102 !, 103 run_command(Open, [URL], fg). 104open_url(URL) :- % user configured 105 getenv('BROWSER', Browser), 106 has_command(Browser), 107 !, 108 run_browser(Browser, URL). 109open_url(URL) :- % something we know 110 known_browser(Browser, _), 111 has_command(Browser), 112 !, 113 run_browser(Browser, URL). 114 115expand_browser_flag(Command-Mode, Command, Mode) :- !. 116expand_browser_flag(Command, Command, bg) :- atomic(Command). 117 118open_command(open) :- % Apples open command 119 current_prolog_flag(apple, true). 120open_command('xdg-open'). % Free desktop 121open_command('gnome-open'). % Gnome (deprecated in favour of xdg-open 122open_command(open). % Who knows 123 124%! run_browser(+Browser, +URL) is det. 125% 126% Open a page using a browser. 127 128run_browser(Browser, URL) :- 129 run_command(Browser, [URL], bg). 130 131%! run_command(+Command, +Args, +Background) 132% 133% Run OS command Command using Args, silencing the error output 134% because many browsers are rather verbose. 135 136:- if(current_predicate(process_create/3)). 137run_command(Command, Args, fg) :- 138 !, 139 process_create(path(Command), Args, [stderr(null)]). 140:- endif. 141:- if(current_prolog_flag(unix, true)). 142run_command(Command, [Arg], fg) :- 143 format(string(Cmd), "\"~w\" \"~w\" &> /dev/null", [Command, Arg]), 144 shell(Cmd). 145run_command(Command, [Arg], bg) :- 146 format(string(Cmd), "\"~w\" \"~w\" &> /dev/null &", [Command, Arg]), 147 shell(Cmd). 148:- else. 149run_command(Command, [Arg], fg) :- 150 format(string(Cmd), "\"~w\" \"~w\"", [Command, Arg]), 151 shell(Cmd). 152run_command(Command, [Arg], bg) :- 153 format(string(Cmd), "\"~w\" \"~w\" &", [Command, Arg]), 154 shell(Cmd). 155:- endif. 156 157%! known_browser(+FileBaseName, -Compatible) 158% 159% True if browser FileBaseName has a remote protocol compatible to 160% Compatible. 161 162known_browser(firefox, netscape). 163known_browser(mozilla, netscape). 164known_browser(netscape, netscape). 165known_browser(konqueror, -). 166known_browser(opera, -). 167 168 169%! has_command(+Command) 170% 171% Succeeds if Command is in $PATH. Works for Unix systems. For 172% Windows we have to test for executable extensions. 173 174:- dynamic 175 command_cache/2. 176:- volatile 177 command_cache/2. 178 179has_command(Command) :- 180 command_cache(Command, Path), 181 !, 182 Path \== (-). 183has_command(Command) :- 184 ( getenv('PATH', Path), 185 ( current_prolog_flag(windows, true) 186 -> Sep = (;) 187 ; Sep = (:) 188 ), 189 atomic_list_concat(Parts, Sep, Path), 190 member(Part, Parts), 191 prolog_to_os_filename(PlPart, Part), 192 atomic_list_concat([PlPart, Command], /, Exe), 193 access_file(Exe, execute) 194 -> assert(command_cache(Command, Exe)) 195 ; assert(command_cache(Command, -)), 196 fail 197 ). 198 199 200 /******************************* 201 * NET PATHS * 202 *******************************/ 203 204%! url_path(+Alias, -Expansion) is nondet. 205% 206% Define URL path aliases. This multifile predicate is defined in 207% module =user=. Expansion is either a URL, or a term Alias(Sub). 208 209:- multifile 210 user:url_path/2. 211 212userurl_path(swipl, 'http://www.swi-prolog.org'). 213userurl_path(swipl_book, 'http://books.google.nl/books/about/\c 214 SWI_Prolog_Reference_Manual_6_2_2.html?\c 215 id=q6R3Q3B-VC4C&redir_esc=y'). 216 217userurl_path(swipl_faq, swipl('FAQ')). 218userurl_path(swipl_man, swipl('pldoc/doc_for?object=manual')). 219userurl_path(swipl_mail, swipl('Mailinglist.html')). 220userurl_path(swipl_download, swipl('Download.html')). 221userurl_path(swipl_pack, swipl('pack/list')). 222userurl_path(swipl_bugs, swipl('bug.html')). 223userurl_path(swipl_quick, swipl('man/quickstart.html')). 224 225%! expand_url_path(+Spec, -URL) 226% 227% Expand URL specifications similar to absolute_file_name/3. The 228% predicate url_path/2 plays the role of file_search_path/2. 229% 230% @error existence_error(url_path, Spec) if the location is not 231% defined. 232 233expand_url_path(URL, URL) :- 234 atomic(URL), 235 !. % Allow atom and string 236expand_url_path(Spec, URL) :- 237 Spec =.. [Path, Local], 238 ( user:url_path(Path, Spec2) 239 -> expand_url_path(Spec2, URL0), 240 ( Local == '.' 241 -> URL = URL0 242 ; sub_atom(Local, 0, _, _, #) 243 -> atom_concat(URL0, Local, URL) 244 ; atomic_list_concat([URL0, Local], /, URL) 245 ) 246 ; throw(error(existence_error(url_path, Path), expand_url_path/2)) 247 )